Internal Loop Recording of Prolonged (39 Second) Sinus Pause Causing Syncope

Presentation: A 53 year old woman presented with a syncopal episode which occurred whilst sitting in bed reading, witnessed by her husband.She was unrousable for maybe half a minute.She had no other medical history, clinical examination was unremarkable, as were multiple investigations.Diagnosis: A loop recorder was inserted without difficulty.A few weeks later she again blacked out.Her loop recorder showed asystole for 39 seconds, followed by a return to sinus bradycardia and then sinus rhythm, accompanied by recovery of consciousness.Treatment: She went on to have a dual chamber pacemaker inserted.At review after six weeks, six months and one year she had had no further syncopal episodes.Conclusion: This case reports one of the longest documented episodes of asystole with spontaneous recovery and serves as a reminder of the utility of internal loop recorders in the investigation of syncope.